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23,540 Article Results

Fast Geometric T2-Fuzzy Based Improved Lower Extremities Stimulation Response

10.12928/telkomnika.v8i3.622
Hendi; Universitas Surabaya Wicaksono
This study emphasizes the use of type-2 fuzzy (T2-Fuzzy) to improve the adaptive proportional-integrative-derivative (PID) control in the lower extremities. Several problems were identified from previous studies and those were the slow achievement of the target angle and the presence of oscillation in the achievement of the target blade. The oscillation occurred as the consequence of deploying the early adaptive PID which was not sufficient to overcome the lower extremities nonlinearity. The difference between proposed method of T2-Fuzzy and the others lies in the defuzzification. This research adopts a fast geometric defuzzification that maintains the level of uncertainty T2-Fuzzy in real-time. A functional electrical stimulation (FES) stimulator is proposed to design and to be connected to the computer for processing the T2-Fuzzy. This stimulator stimulates lower extremities of normal subjects each cycle, and the computer record the point of measured achievement of using a goniometer sensors mounted on a knee joint. The results show that the target point of lower extremities is achieved within three initial cycles without oscillations in the achievement of the angle. It is also found that T2-Fuzzy is able to immediately restore the point of achievement when the external parameters of control occur.
Volume: 8
Issue: 3
Page: 207-216
Publish at: 2010-12-01

A Video Streaming Application Using Mobile Media Application Programming Interface

10.12928/telkomnika.v8i3.631
Ary Mazharuddin; Sepuluh Nopember Institute of Technology Shiddiqi , Henry; Sepuluh Nopember Institute of Technology Pratama , Henning Titi; Sepuluh Nopember Institute of Technology Ciptaningtyas
Recently, the development of mobile phone technology is growing rapidly. These developments led to the emerging of a multimedia mobile phone that supports Wireless Local Area Network (WLAN). However, the use of WLAN technology on mobile phones to access the streaming video is very rarely employed, while the current S60 Symbian operating system as a multimedia mobile phone is very reliable in handling a video. This study presents the making of a video streaming application in mobile phone via a WLAN connection using JSR 135 technology or the Mobile Media API (MMAPI). MMAPI is used to control the process of video streaming and its features. The application uses the two protocols; RTSP and HTTP. Experiment results show that the use of MMAPI on Symbian 60 based mobile phones to do video streaming is feasible and has a good reliability as 0% packet loss on connection. In addition, the times required to play multimedia files are not affected by the size of video streaming files.
Volume: 8
Issue: 3
Page: 293-300
Publish at: 2010-12-01

Lag-Lead Compensator for Shape Memory Alloy in Gripping Manipulation

10.12928/telkomnika.v8i3.626
Made Andik; Politeknik Manufaktur (Polman) Timah Bangka Belitung Setiawan
Shape Memory Alloy (SMA) is emerging actuator for micro and nano application which is interesting to be developed. This paper presents the evaluation of close-loop controller responses of the TiNi SMA spring based gripper by introducing lag, lead and lag-lead compensator. A SMA spring has a diameter of 50 mm wire and 350 gram hanging mass. The driver of the SMA actuator uses pulse width modulation (PWM) signal and it is tested by varying frequencies and duty-cycles. The applied frequencies in this study are 12, 25, 125, 250 and 1150 Hz. Lab-View and DAQ-Card is used as a controller, interfacer and data recorder of the system. The fabricated gripper consists of two fingers and the total angular displacement of the gripper is 300. In advanced application, the experiment coversSMA open loop and close-loop system. The SMA response indicated that the rise-time and the steady-state error of the cloop-loop are shorter and lower than open-loop controller.
Volume: 8
Issue: 3
Page: 245-254
Publish at: 2010-12-01

Cost and Benefit of Information Search using Two Different Strategies

10.12928/telkomnika.v8i3.621
Paulus Insap; UGM Santosa
Searching for information is one major Internet activities during which information seekers may gain benefit as well as incurred some cost. In general, information seekers seldom employ any search strategy for general browsing to explore information space. On the other hand, in certain situation, they may employ certain search strategy, especially those who engage in a fact-finding activity. The objective of this research is to shed light on how search strategy can be used to gain the maximum benefit of information search activities. It borrows the two-factor theory to group Web design elements into benefit and cost manifested as motivating and hygiene factors. This research employed a laboratory experiment with 235 respondents who were participated on this research voluntarily. Respondents were divided into two groups, namely ‘plan-group’ and ‘unplan-group’. Both groups were given certain tasks related to information search. The experiment was followed by a post experiment survey. The result shows that respondents who were in the ‘plan-group’ perceived less benefit and incurred more cost compared to those in the ‘unplan-group’. The future research is proposed at the end of this manuscript.
Volume: 8
Issue: 3
Page: 195-206
Publish at: 2010-12-01

Distributed Monitoring and Controlling Using Microcontroller and Virtual Internet Protocol

10.12928/telkomnika.v8i3.630
Ahmad; Gadjah Mada University (UGM) Ashari
Nowadays, the applications based on TCP/IP (transmission control protocol/internet protocol) network are growing rapidly. By this application monitoring and control functions are easily and widely accessible through networks. Every PC (Personal Computer) can be connected to several microcontroller, but there are difficulties to access microcontroller directly through TCP/IP networks. This research study the use of virtual IP on a PC that connected with several microcontrollers, where each microcontroller is connected to a sensor device to monitoring temperature and a relay for controlling. In this method, each set of the microcontroller can be accessed directly using the IP. The results show that this system can be a distributed monitoring and controlling system which has the ability to record and display the results in the form of graphs. 
Volume: 8
Issue: 3
Page: 285-292
Publish at: 2010-12-01

Harmonic Mitigation Using a Polarized Ramp-time Current-Controlled Inverter

10.12928/telkomnika.v8i3.625
Hanny; Petra Christian University H. Tumbelaka , Lawrence; Aquila Electronics J. Borle
 This paper describes the implementation of a shunt active power filter for a three-phase four-wire system to overcome the power quality problems generated by mixed non-linear loads which are a combination of harmonic, reactive and unbalanced components. The filter consists of a three-phase current-controlled voltage source inverter (CC-VSI) with a filter inductor at the AC output and a DC-bus capacitor. The CC-VSI is operated to directly control the grid current in order to be sinusoidal and in phase with the grid voltage without sensing the load currents. The switching is controlled by using polarized ramp-time current control, which is based on the concept of zero average current error (ZACE) with a fixed switching frequency. The laboratory experiment results indicate that the filter is able to mitigate the harmonics and the reactive power, so that the grid currents are sinusoidal, in phase with the grid voltages, and symmetric although the grid voltage contains harmonics.
Volume: 8
Issue: 3
Page: 235-244
Publish at: 2010-12-01

An Adaptive Modulation in Millimeter-Wave Communication System for Tropical Region

10.12928/telkomnika.v8i3.634
Suwadi; Institut Teknologi Sepuluh Nopember Surabaya Suwadi , Gamantyo; Institut Teknologi Sepuluh Nopember Surabaya Hendrantoro , Wirawan; Institut Teknologi Sepuluh Nopember Surabaya Wirawan
 The dominant propagation factor affecting the outage and the spectral efficiency of millimeter-wave communication systems operating at frequencies 30 GHz is rain attenuation. An adaptive modulation is proposed to improve the outage and spectral efficiency performance of the system. This paper presents an analytical procedure for the evaluation of the outage and spectral efficiency of the system in Indonesia with heavy rain rate. By comparing analytic and simulation a validation was conducted. The results show that adaptive modulation can significantly improve the outage and the spectral efficiency performance of the system, for links with long distance.
Volume: 8
Issue: 3
Page: 319-326
Publish at: 2010-12-01

A Novel Dynamic Overmodulation Strategy of Direct Torque Control

10.12928/telkomnika.v8i3.629
Auzani; Universiti Teknikal Malaysia Melaka (UTeM) Jidin , Tole; Universitas Ahmad Dahlan (UAD) Sutikno , Aiman Zakwan; Ecole Supérieur d’Ingénieur en Electronique et Electrotechnique (ESIEE Engineering Paris) Jidin , Nik Rumzi Nik; Universiti Teknologi Malaysia (UTM) Idris , Abdul Halim Mohd; Universiti Teknologi Malaysia (UTM) Yatim
The direct torque control-space vector modulation (DTC-SVM) is well-known for achieving excellent dynamic overmodulation. However, the method uses complicated predictive stator flux vector control and requires high precision stator flux vector to define overmodulation mode. This paper proposes a straightforward dynamic overmodulation method and constant switching frequency controller without SVM to obtain a faster dynamic torque response in DTC for induction machines. To perform this method, the flux error status produced from the flux hysteresis comparator during dynamic condition is modified slightly before being fed to the look-up table. The verification of proposed method was performed using MATLAB/Simulink simulation package. The effects of different switching and operating condition on dynamic torque performance are analyzed. The result shows that a faster torque response is achieved in proposed dynamic overmodulation DTC method. The main benefit of the proposed method is its simplicity since only minor modification is made to the basic DTC hysteresis-based structure. 
Volume: 8
Issue: 3
Page: 275-284
Publish at: 2010-12-01

A REAL-TIME LICENSE PLATE DETECTION SYSTEM FOR PARKING ACCESS

10.12928/telkomnika.v8i2.610
Fajar Astuti; University of 17 Agustus 1945 of Surabaya Hermawati , Roenadi; University of 17 Agustus 1945 of Surabaya Koesdijarto
The automatic and real-time license plate detection system can be used as an access control entry of vehicles into the parking area. The problem is how to recognize the vehicles that will go into the parking lot and how to recognize various types of license plates in various light conditions quickly and accurately. In this research, the prototype was developed with a detection system to recognize the vehicles that will enter the parking area, and a license plate recognition system. In the license plate recognition system, the Fourier transform and Hidden Markov model method have proposed to detect location of license plate and as  characters segmentation to recognize Indonesia license plates. The research results have shown that the developed prototipe system has successfully recognized all Indonesia license plates in several of light condition and camera position. The percentage of plate recognition in the real-time experiment is 84.38%, and the average execution time for all recognition process is 5.834 second.
Volume: 8
Issue: 2
Page: 97-106
Publish at: 2010-08-01

A UNIFIED ENERGY APPROACH FOR B-SPLINE SNAKE IN MEDICAL IMAGE SEGMENTATION

10.12928/telkomnika.v8i2.619
Agung; Indonesia Islamic University Alfiansyah
 The parametric snake is one of the preferred approaches in feature extraction from images because of their simplicity and efficiency. However the method has also limitations. In this paper an explicit snake that represented using BSpline applied for image segmentation is considered. In this paper, we identify some of these problems and propose efficient solutions to get around them. The proposed method is inspired by classical snake from Kass with some adaption for parametric curve. The paper also proposes new definitions of energy terms in the model to bring the snake performance more robust and efficient for image segmentation. This energy term unify the edge based and region based energy derived from the image data. The main objective of developed work is to develop an automatic method to segment the anatomical organs from medical images which is very hard and tedious to be performed manually. After this segmentation, the anatomical object can be further measured and analyzed to diagnose the anomaly in that organ. The results have shown that the proposed method has been proven qualitatively successful in segmenting different types of medical images. 
Volume: 8
Issue: 2
Page: 175-186
Publish at: 2010-08-01

SEBUAH ALGORITMA POHON KEPUTUSAN UNTUK KLASIFIKASI CITRA SATELIT AQUA MODIS

10.12928/telkomnika.v8i2.614
Rina Luciane; Politeknik Negeri Ambon Manuhutu , Riana Debora; Politeknik Negeri Ambon Hutagalung
The satellite image processing for the environmental eksploration requires data accuracy which implied in every pixel of image so that required an appropriate technique of classification. The suitable classification is decition tree classification technique. Research about decition tree classification for classification data of satellite image have done and also research about Aqua MODIS satellite image processing for environmental exploration, but the decition tree classification technique is not developed yet for the classification of Aqua MODIS satellite data image. In this research, an algorithm decition tree classification method for data processing of Aqua MODIS satellite image to determine sea surface temperature classification is developed. A case study conducted at territorial Moluccas waters. The result of this research show that mean of accuration data classification of sea surface temperature is 97.6%
Volume: 8
Issue: 2
Page: 131-136
Publish at: 2010-08-01

ENHANCED NEURO-FUZZY ARCHITECTURE FOR ELECTRICAL LOAD FORECASTING

10.12928/telkomnika.v8i2.609
Hany; Petra Christian University Ferdinandoa , Felix; Petra Christian University Pasila , Henry; Petra Christian University Kuswanto
Previous researches about electrical load time series data forecasting showed that the result was not satisfying. This paper elaborates the enhanced neuro-fuzzy architecture for the same application. The system uses Gaussian membership function (GMF) for Takagi-Sugeno fuzzy logic system. The training algorithm is Levenberg-Marquardt algorithm to adjust the parameters in order to get better forecasting system than the previous researches. The electrical load was taken from East Java-Bali from September 2005 to August 2007. The architecture uses 4 inputs, 3 outputs with 5 GMFs. The system uses the following parameters: momentum=0.005, gamma=0.0005 and wildness factor=1.001. The MSE for short term forecasting for January to March 2007 is 0.0010, but the long term forecasting for June to August 2007 has MSE 0.0011. 
Volume: 8
Issue: 2
Page: 87-96
Publish at: 2010-08-01

A FUZZY LOGIC CLASSIFICATION OF INCOMING PACKET FOR VOIP

10.12928/telkomnika.v8i2.618
Suardinata; Universiti Teknologi Malaysia, STMIK Indonesia Padang Suardinata , Kamalrulnizam Bin Abu; STMIK Indonesia Padang Bakar
The Voice over Internet Protocol (VoIP) technology is cheaper and does not need new infrastructure because it has availables in the global computer (IP) network. Unfortunately, transition from PSTN to VoIP networks have emerged new problems in voice quality. Furthermore, the transmission of voice over IP networks can generate network congestion due to weak supervision of the traffic incoming packet, queuing and scheduling. This congestion affects the Quality of Service (QoS) such as delay, packet drop and packet loss. Packet delay effects will affect the other QoS such as: unstable voice packet delivery, packet jitter, packet loss and echo. Priority Queuing (PQ) algorithm is a popular technique used in the VoIP network to reduce delays. But, the method can result in repetition. This recursive leads to the next queue starved. To solving problems, there are three phases namely queuing, classifying and scheduling. It will be applied to the fuzzy inference system to classify the queuing incoming packet (voice, video and text). To justify the research of the improved PQ algorithm be compared against the algorithm existing.
Volume: 8
Issue: 2
Page: 165-174
Publish at: 2010-08-01

IMPROVED VOLTAGE OF CASCADED INVERTERS USING SINE QUANTIZATION PROGRESSION

10.12928/telkomnika.v8i2.613
Bambang; Universitas Jember Sujanarko , Mochamad; Institut Teknologi Sepuluh Nopember (ITS) Surabaya Ashari , Mauridhi Hery; Institut Teknologi Sepuluh Nopember (ITS) Surabaya Purnomo
The previous methods of cascaded multilevel inverter (CMLI) can improve power quality but the methods have low voltage output if the DC voltages limited by the voltage rating of power semiconductor. To improve the amplitude of CMLI output voltage, this paper proposes a new DC voltage progression. The progression based on sine quantization method (SQM), which determines a sequence of DC voltages from discrete amplitudes of sine wave function. The method also collaborates with step equal residual area method (SERAM) to minimized total harmonics distortions (THD). A single-phase CMLI that consist four H-Bridges simulated and implemented to verify the methods. Amplitude output voltage and THD results of simulations and experiments indicate that the sine quantization progression produce the highest output voltage than other DC voltage progressions, with power quality or THD in the accepted region. The amplitude of output voltage have linier function with amplitude equal 0.6665 times of H-Bridges numbers and have exponential function of THD with value below 5%.
Volume: 8
Issue: 2
Page: 123-130
Publish at: 2010-08-01

SEBUAH MODEL BERBASIS PENGETAHUAN UNTUK PENGENDALIAN FORMASI SISTEM ROBOT MAJEMUK

10.12928/telkomnika.v8i2.608
Andi; Universitas Mercu Buana Adriansyah
Study of multi-robot system has been popular in recent years. This system is able to reduce processing time of some processes, the cost and complexity of the system. However, multi-robot system also has some problems. One of the problems faced by these systems is how to control robots in a certain formation when carrying out its functions. Several methods have been offered to resolve the existing problems. This study tries to offer a method to solve the problem, by modeling the multi-robot systems and implement a control system in order to maintain a specific formation. The study attempted to use a controller based on knowledge base system. Model is developed using MATLAB software and simulated to determine the performance. Several experiments are conducted to determine the movement of the robot and its ability to maintain a specific formation. From the experiments it can be said that the modeling of multiple-robot system has been reliable. In addition, formation control actions have also been running well, although there should be further development.
Volume: 8
Issue: 2
Page: 81-86
Publish at: 2010-08-01
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